Department of Physics, Engineering Physics & Astronomy

Department of Physics, Engineering Physics & Astronomy
Department of Physics, Engineering Physics & Astronomy

Correlations in Low Dimensional Electron Systems: Electron-hole bilayers and Quantum Dot Molecules

Ramin Abolfath
National Research Council - Institute for Microstructural Sciences

Wednesday, October 19, 2005
10:30 AM @ Stirling 501

Abstract:

In this talk I review some of the properties of coupled quasi-two-dimensional electron systems in strong magnetic field. I focus on the role of hybridization between electrons in opposite layers and dots. Condensation of electron-hole bilayers which exhibit excitonic superfluid ground states with counter propagating super-currents is addressed [1]. Recent drag experiments and supercurrent measurements are pointed out. Then I present a theory of laterally coupled quantum Hall droplets with electron numbers (N1,N2) at filling factor 2. The edge states of each droplet are tunnel coupled and form a two-level artificial molecule. By populating the edge states with one electron each, a two electron molecule is formed. We predict the singlet-triplet transitions of the effective two-electron molecule as a function of the magnetic field, the number of electrons, and confining potential using the configuration interaction method coupled with the unrestricted Hartree-Fock (URHF) basis [2].
[1] M. Abolfath, A. H. MacDonald, and L. Radzihovsky, Phys. Rev. B 68, 155318 (2003).
[2] Ramin M. Abolfath, W. Dybalski, Pawel Hawrylak, cond-mat/0509585.